Tall grass and large ferns are not affected by fortune

Fortune increases the amount of seeds dropped by grass and ferns, but the same cannot be said for tall grass and large ferns.

Loot table for tall grass that controls this:

{
  "type": "minecraft:item",
  "conditions": [
    {
      "condition": "minecraft:survives_explosion"
    },
    {
      "condition": "minecraft:block_state_property",
      "block": "minecraft:tall_grass",
      "properties": {
        "half": "lower"
      }
    },
    {
      "condition": "minecraft:random_chance",
      "chance": 0.125
    }
  ],
  "name": "minecraft:wheat_seeds"
}

And here's the loot table for grass:

{
  "type": "minecraft:item",
  "conditions": [
    {
      "condition": "minecraft:random_chance",
      "chance": 0.125
    }
  ],
  "functions": [
    {
      "function": "minecraft:apply_bonus",
      "enchantment": "minecraft:fortune",
      "formula": "minecraft:uniform_bonus_count",
      "parameters": {
        "bonusMultiplier": 2
      }
    },
    {
      "function": "minecraft:explosion_decay"
    }
  ],
  "name": "minecraft:wheat_seeds"
}